Satelitte Attacks

[kalos72]

Is there a documented timeline for when there was this supposed satellite attacks?

What's the consensus, does this population believe that every single satellite is dead by 2000/2001?

[Matt Wiser]

The birds in GEO and HEO (High Earth Orbit) are safe. It's the LEO ones-reconsats, for example, that would be vulnerable to ASAT attack.

As for timeline? Once the U.S. entered the war, that's when the F-15s with ASAT missiles got turned loose, and the Soviets responded with their ground-based system.

[kalos72]

Ok that makes sense then...thanks.

What type of satellites live in those safe zones?

There are many accounts of the satellites being "dead" so things like communications and the like being down a well. Is that more earth based tech issues or satellites?

[swaghauler]

Originally Posted by Matt Wiser

The birds in GEO and HEO (High Earth Orbit) are safe. It's the LEO ones-reconsats, for example, that would be vulnerable to ASAT attack.

As for timeline? Once the U.S. entered the war, that's when the F-15s with ASAT missiles got turned loose, and the Soviets responded with their ground-based system.

This! I've always had the debate that the GPS satellites were so important to the West that they would be protected at all costs. Even duplicate ground stations exist for GPS. I think the original developers were unaware of just how important they were to the Airforce and the Navy.

That being said, I could see CONSIDERABLE gaps forming in the GPS coverage (like a 50-50 chance of getting a signal), especially for ground units. I know that in the Allegheny National Forest today, you only have about a 75% chance of finding a GPS signal through the canopy. I can only imagine how much harder to get triangulation it would be in Twilight2000.

[Comanche]

1st post so I apologize if I screw something up.

found a diagram of various orbits:
https://upload.wikimedia.org/wikiped...ion_orbits.svg

from wikipedia - based on a short search (30 min) for asat weapons I don't think the GPS would be able to be targeted. That's not to say there wouldn't be problems from the nuclear exchanges (damaged - destroyed ground stations) or maintenance issues.

[Comanche]

1st post so I apologize if I screw something up.

found a diagram of various orbits:
https://upload.wikimedia.org/wikiped...ion_orbits.svg

from wikipedia - based on a short search (30 min) for asat weapons I don't think the GPS would be able to be targeted. That's not to say there wouldn't be problems from the nuclear exchanges (damaged - destroyed ground stations) or maintenance issues.

[lordroel]

I would assume that the US is not able to replace losses suffer to satellites during and after the war for some time.

[RN7]

Some discussion about this and space warfare on earlier threads.

http://forum.juhlin.com/showthread.php?t=4207

http://forum.juhlin.com/showthread.p...ght=satellites

[The Dark]

Originally Posted by swaghauler

This! I've always had the debate that the GPS satellites were so important to the West that they would be protected at all costs. Even duplicate ground stations exist for GPS. I think the original developers were unaware of just how important they were to the Airforce and the Navy.

That being said, I could see CONSIDERABLE gaps forming in the GPS coverage (like a 50-50 chance of getting a signal), especially for ground units. I know that in the Allegheny National Forest today, you only have about a 75% chance of finding a GPS signal through the canopy. I can only imagine how much harder to get triangulation it would be in Twilight2000.

GPS satellites would be hard to knock down. They're at ~20,200 kilometers altitude (and GLONASS is at 19,100 kilometers, not much easier). The only ASM-135 ASAT test hit Solwind P78-1 at 555 kilometers. Iridium satellites would be more vulnerable; they're only at about 781 kilometers.

The Soviet IS system worked at least moderately well, but it was canceled in 1983, well before any of the Twilight War scenarios. The last armed Almaz station had deorbited in 1977, Terra-3 and Fon both failed, and Polyus/Skif broke up after separation from Energiya in 1987. The Vympel bureau tried to integrate an ASAT on the MiG-31 Foxhound, but it was a troubled program that wasn't ready before the breakup of the Soviet Union.

[rcaf_777]

Originally Posted by swaghauler

I think the original developers were unaware of just how important they were to the Airforce and the Navy.

I wouldn't say that, it just dose not play an important role in the overall game play.

Think about it, your trapped in Poland, ok now what hey guys, which way do we go? Well like the song says we go west. Even with out a map or compass you easily find west....use the sun. Besides unless you really evil GM I'm sure a PC group would at some point find a map

Who needs a GPS. Other mods are the same way.

If you like an area like the Allegheny National Forest, you will find tons of highways, trails, roads you can use to figure out which way to go.

Besides GPS use batteries which will run out, so forget about the signal where are you going to find spare batteries? or recharge the ones you might have?

And finally if GPS is so important to the Airforce and Navy, why is Loran-C and Tactical air navigation system (TACAN) still in use?

kalos72 if you want to find a good robust communication system for NA, my suggestion is shortwave/amateur radio stations. Equipment is only a radio shack away, it easy to hid in case the authorities drops by. And they could also be use to broadcast propaganda. The down size is that its not hard to intercept and or Jam signals. A code book would solve some issues, but not all.

[kalos72]

Well, I was looking at more international communications. How do I speak to the MILGOV forces in Korea for example?

There are indications at least that were still some working comms from Colorado to Korea and maybe Iran but the writing implies those are hanging on by a string, and when it breaks?

I guess civilian radios are an option but obviously a working military radio network would be optimal, although apparently not very possible.

[Silent Hunter UK]

Radio hams could probably bounce signals off the atmosphere... I don't know the technical matters, but it was possible to send wireless signals over the Atlantic before the war.

[rcaf_777]

Originally Posted by kalos72

Well, I was looking at more international communications. How do I speak to the MILGOV forces in Korea for example?

There are indications at least that were still some working comms from Colorado to Korea and maybe Iran but the writing implies those are hanging on by a string, and when it breaks?

I guess civilian radios are an option but obviously a working military radio network would be optimal, although apparently not very possible.

Well comms in Colorado could be the Green Pine UHF communications system, or AN/FRC-117 Survivable Low Frequency Communications System (SLFCS) which uses UHF and VLF both are part of the Post-Attack Command and Control System.

There is also AN/URC-117 Ground Wave Emergency Network, which also could be used although this was network was cancelled in 1994, 58 towers where built and more could built at the start of the Twilight war.

There are also several organizations that could help out the military with overseas communications they are:

Radio Amateur Civil Emergency Service(RACES)
American Radio Relay League (ARRL)
Military Auxiliary Radio System (MARS)

Also your idea of launching some small comms satellites, is something the USAF had in their AN/DRC-8 Emergency Rocket Communications System although is was canceled in 1991, it might be modified and used in 2000/01 if the USAF has any Minuteman II left

https://en.wikipedia.org/wiki/AN/DRC...cations_System

[swaghauler]

Originally Posted by kalos72

Well, I was looking at more international communications. How do I speak to the MILGOV forces in Korea for example?

There are indications at least that were still some working comms from Colorado to Korea and maybe Iran but the writing implies those are hanging on by a string, and when it breaks?

I guess civilian radios are an option but obviously a working military radio network would be optimal, although apparently not very possible.

Check out Single Side Band Radio. It is a variation of long range AM radio transmissions that reduces the power needed to transmit. A 1000 Watt AM radio using a SSB filter would use the same power as a 125 Watt AM radio to transmit a message. This, combined with the already mentioned "sky wave propagation" will allow global communications on a "power budget." SSB is used extensively by blue water sailors for communicating with each other and the rest of the world.

Another "plot device" you could look at is a satellite "ground station" that wasn't destroyed. It could be abandoned or in "other hands" and still "talking" to a existing satellite. Taking the station (and by extension, control of the satellite), could be a good adventure plot.

[swaghauler]

Originally Posted by rcaf_777

Besides GPS use batteries which will run out, so forget about the signal where are you going to find spare batteries? or recharge the ones you might have?

And finally if GPS is so important to the Airforce and Navy, why is Loran-C and Tactical air navigation system (TACAN) still in use?

I'm not trying to offend you here, but... are you joking (I'm sensing a bit of sarcasm in your reply)?

Loran-C: Loran uses very large radio towers (requiring huge amounts of power) to beam directional signals which can be picked up by receivers to tell bearing (direction to the transmitter). The transceiver is small (about the size of a car stereo) and not very expensive (I still have one on my boat), but the transmitters are HUGE (like 1,000 feet tall for the transoceanic ones). Furthermore, they have a limited range of about 500 Nautical Miles per station. This is why there are "chains" of identical stations (often containing a "master" and one or more "slave" transmitters) for long range navigation. The accuracy of Loran-C is about 100 meters per kilometer over most ranges (it is better if you are traveling shorter ranges because the radio waves aren't as distorted). This means that a ship traveling 5,000km will be off on its navigation by about 50km if they used Loran alone (assuming perfect weather which also degrades the Loran's signal). The average accuracy combining "Dead Reckoning" WITH multiple Loran-C fixes during the voyage is about 1km per 1000km. That ship traveling 5000km will be off 5km at the end of their voyage. While 5km may not seem like much, it assumes very good Dead Reckoning navigation in addition to the Loran-C fixes.

Additionally, if the Soviets are attacking the GPS satellites, there is NO WAY they are going to allow the Loran network to keep transmitting. All it would take to shut down the Loran-C system (besides the loss of the power grid) are a few HARM missiles.

VOR/DME NAVIGATION (VHF Omni-Directional Ranging/Distance Measuring Equipment: This civilian radio ranging and bearing system uses two separate systems and is commonly used by Commercial Aviation for determining bearings (VOR) and range (DME) to an airport. This is a VHF radio beacon system that is easily jammed and only useful at a limited range (about 300km). It provides 2-DIMENSIONAL ranging (ILS is 3-dimensional) to an airport and can produce SIGNIFICANT errors in Slant Ranging of aircraft (slant range is both the distance AND altitude to the airport). Ranging errors can be from 400m to 900m with altitude variations being the more common error. This is why VOR/DME is only authorized for NON-PRECISION Approaches to an airport. It is too inaccurate for a Precision Approach. Attempts to correct this resulted in the TDME (or Terminal DME) where a 0 on range means you are at the head of the runway. The downside to TDME is that it is STILL a 2-D system, you may be at the end of the runway in distance, but there is no "calculation" for altitude (like with ILS).

The system uses both a transmitter (at the airport) and a TRANSCEIVER (in the aircraft). The aircraft's transceiver "pings" the transmitter and the transmitter replies. This means that BOTH the aircraft and the airport are emitting signals that can be easily tracked and triangulated (especially since they are VHF). Once again, a HARM missile would end this system's "life."

TACAN (Tactical Air Navigation Unit): This more accurate "cousin" to VOR/DME uses a similar system but in the MHz range. The system in the 90's was fairly ponderous (800lbs) and used a significant amount power (10kw) given its maximum range of 390 Nautical Miles. Modern systems are much smaller and more economical (100lbs and 400 watts) but both still have the drawback of emitting large amounts of EM energy which can be detected and triangulated. A carrier turning on its TACAN is essentially a "sitting duck" until the aircraft are retrieved. Modern (21st Century) TACAN have an interrogation mode that only turns the system on if "interrogated" by a "friendly transceiver" (using IFF systems) and then stays on just long enough to provide range and bearing info before shutting off again. The modern transceiver has 3 settings: Recieve (no outgoing "ping") gives the range to the TACAN only. Transmit/Recieve ("pinging" the TACAN) gives both range AND bearing to the TACAN. Finally, 21st Century TACAN Transceivers have an Air-To-Air setting which gives Slant Range and Bearing to another transceiver equipped aircraft. The accuracy of TACAN is about 20m per Kilometer which is VERY GOOD. Even though this is good, TACAN is being replaced by JPALS (a binary GPS system with an accuracy of 1 meter).

The Global Positioning System (GPS): The GPS system uses space-based satellites combined with PASSIVE RECEIVERS to perform triangulation to determine your EXACT position on the Earth. The US government, worried about misuse, degraded the civilian receivers so that you could only get an accuracy of 20 meters from your requested location (President Clinton ended this in 2000). Military personnel were getting 3-meter accuracy readings during the Twilight War. Additionally, since the receivers were passive (emitting no signal themselves), the enemy could not detect the user. The receivers are also small, use minimal power, and cheap (unfortunately, the satellites aren't). The accuracy of GPS was an "order of magnitude" better than radio-based navigation.

Things are not all "sunshine and puppies" though. The GPS receivers can be jammed locally and the satellites are subject to EM interference in space. Local weather or overhead cover can interfere with the signal as well, but strategically, GPS is "unjammable" across the globe. The accuracy of GPS was so good, that civilian mariners began to ignore other types of navigation.
All it took was one instant of forgetting about the 20-meter "bias" the government installed, and you had yourself what the Coast Guard called "A GPS-assisted grounding."

Navigation in the Game:

In response to your first statements about general direction finding, I would say "yes and no." People get lost following road maps and street signs all the time. The real test comes when you have to travel to a PRECISE LOCATION which you have NEVER been to before. I like to throw in "Navigational Tests" during gameplay (usually with a time constraint as well) to change things up. The ultimate test; Navigating the Desert or Jungle in the dark (no "terrain association" here boys). So GPS is VERY important to my players. It means the difference between an Easy:Navigation or a Formidable:Navigation test.